The educational landscape has changed tremendously with the arrival of open educational resources (OER) and has become a mission-driven trend within the scientific literature. In the current study, bibliometric analysis and an analysis of the challenges and limitations of the research articles on recent developments in the field of OER were performed. Scopus was chosen as the prime source for collecting bibliographical data, focusing on five sub-themes, i.e., open textbook, open online course, open courseware, open-source software related to open education, and open social learning. Bibliometric analyses were made based on several aspects, including research trend, research subject distribution, journals, institutions, countries/territories, and authors. This paper summarizes the growth structure of OER from 2002 to 2020 and provides a concise background overview of the works related to OER, barriers, and challenges.